/*
 * Copyright 2010 Google Inc.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */
package com.cleangwt.cell.client;

import java.util.Date;

import com.google.gwt.cell.client.AbstractCell;
import com.google.gwt.cell.client.Cell;
import com.google.gwt.i18n.client.DateTimeFormat;
import com.google.gwt.i18n.client.DateTimeFormat.PredefinedFormat;
import com.google.gwt.i18n.client.TimeZone;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
import com.google.gwt.text.shared.SafeHtmlRenderer;
import com.google.gwt.text.shared.SimpleSafeHtmlRenderer;

/**
 * A {@link Cell} used to render a date box.
 */
public class DateCell extends AbstractCell<Number> {

  private final DateTimeFormat format;

  private final SafeHtmlRenderer<String> renderer;

  private final TimeZone timeZone;

  /**
   * Construct a new {@link DateCell} using the format {@link PredefinedFormat#DATE_FULL} and a
   * {@link SimpleSafeHtmlRenderer}.
   */
  public DateCell() {
    this(DateTimeFormat.getFormat(PredefinedFormat.DATE_FULL),
        SimpleSafeHtmlRenderer.getInstance(), null);
  }

  /**
   * Construct a new {@link DateCell} using the specified format and a
   * {@link SimpleSafeHtmlRenderer}.
   * 
   * @param format the {@link DateTimeFormat} used to render the date
   */
  public DateCell(DateTimeFormat format) {
    this(format, SimpleSafeHtmlRenderer.getInstance(), null);
  }

  /**
   * Construct a new {@link DateCell} using the specified format and the given
   * {@link SafeHtmlRenderer}.
   * 
   * @param format the {@link DateTimeFormat} used to render the date
   * @param renderer a non-null {@link SafeHtmlRenderer} used to render the formatted date
   */
  public DateCell(DateTimeFormat format, SafeHtmlRenderer<String> renderer) {
    this(format, renderer, null);
  }

  /**
   * Construct a new {@link DateCell} using the specified format, the given {@link SafeHtmlRenderer}
   * , and the specified time zone.
   * 
   * @param format the {@link DateTimeFormat} used to render the date
   * @param renderer a non-null {@link SafeHtmlRenderer} used to render the formatted date
   * @param timezone the {@link TimeZone} used to render the date, or null to use the default
   *          behavior for the local time zone and the rendered date. See
   *          {@link DateTimeFormat#format(Date)} and {@link Date#getTimezoneOffset()}
   */
  public DateCell(DateTimeFormat format, SafeHtmlRenderer<String> renderer, TimeZone timeZone) {
    if (format == null) {
      throw new IllegalArgumentException("format == null");
    }
    if (renderer == null) {
      throw new IllegalArgumentException("renderer == null");
    }
    this.format = format;
    this.renderer = renderer;
    this.timeZone = timeZone;
  }

  /**
   * Construct a new {@link DateCell} using the specified format and time zone.
   * 
   * @param format the {@link DateTimeFormat} used to render the date
   * @param timezone the {@link TimeZone} used to render the date, or null to use the default
   *          behavior for the local time zone and the rendered date. See
   *          {@link DateTimeFormat#format(Date)} and {@link Date#getTimezoneOffset()}
   */
  public DateCell(DateTimeFormat format, TimeZone timeZone) {
    this(format, SimpleSafeHtmlRenderer.getInstance(), timeZone);
  }

  /**
   * Construct a new {@link DateCell} using the format {@link PredefinedFormat#DATE_FULL} and a
   * {@link SimpleSafeHtmlRenderer}.
   * 
   * @param renderer a non-null {@link SafeHtmlRenderer} used to render the formatted date as HTML
   */
  public DateCell(SafeHtmlRenderer<String> renderer) {
    this(DateTimeFormat.getFormat(PredefinedFormat.DATE_FULL), renderer, null);
  }

  @Override
  public void render(Context context, Number value, SafeHtmlBuilder sb) {
    if (value != null) {
      sb.append(renderer.render(format.format(new Date(value.longValue()), timeZone)));
    }
  }
}
